It really does come down to coverage and (as you say) congestion/oversubscription. I've used a cheap ($30/mo) prepaid plan on TMo for the past several years an

It really does come down to coverage and (as you say) congestion/oversubscription. I've used a cheap ($30/mo) prepaid plan on TMo for the past several years and it's only gotten better in my city. Just ran speed tests on 3 different sites from my office (with passable signal strength but not "full bars" and without checking actual numbers). All three claimed 24-25Mbps download and 5-8Mbps upload with 65-75ms latency. This is more than enough for my cell phone, but I'd imagine any drops or latency would be a lot more noticeable if I was tethered to a laptop. I guess for me, the main uses of cellular data are web browsing and media streaming when I'm not at home or at the office (when I'd be on WiFi instead). This is plenty for me and I even get coverage outside of the city these days. 5 years ago I might not have said the same.